ASoC: rt5640: Move checking of device-properties to component probe callback

On some platforms the platform code may need to add device-properties,
rather then relying only on properties set by the firmware.

This commit moves the parsing of the device-properties from the i2c-driver
probe() function, which may be called at any time, to the component-driver
probe() function, which gets called after the platform code calls
snd_soc_register_card().

This allows the platform code to attach extra device-properties before
the device-properties are parsed.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mark Brown <broonie@kernel.org>